The event was a watershed moment for 1960s America, which was still putting the assassination of President Kennedy in the past. Though the Vietnam War and resulting social upheaval were only just getting underway, the fair exhibited the nation's postwar optimism of a bright, technological future.

Spanning two six-month seasons from April 1964 to October 1965, the fair was full of space-age futurism, newfangled technologies, and more than its share of controversy.

In honor of the anniversary, we’ve collected these photos from the fair:

The 1964-1965 fair was the third major World’s Fair to be held in New York City. The theme of the '64 fair was Peace Through Understanding and was symbolized by a 12-story stainless-steel model of the Earth called the Unisphere. It was built by U.S. Steel.